1. Field of the Invention
This invention relates to fuels for internal combustion engines and more particularly to a novel process whereby a hazy alcohol-gasoline motor fuel composition can be converted to a clear, stable blend to about -10.degree. F.
The use of aliphatic alcohols such as methanol and ethanol to extend gasoline fuels while imparting a higher octane rating to the gasoline has been desired for some time. However, alcohol-gasoline blends have a low tolerance for water that is encountered in the blending and distribution systems. Methanol-gasoline blends are much less water tolerant than ethanol-gasoline blends. Unstable hazy blends may result when water is present in such systems and/or when there is a sudden drop in ambient temperature. Hazy gasolines are unacceptable by the public since they may indicate that the fuel may be contaminated or perform unsatisfactorily. Further, phase separation may occur with water and alcohol separating out and contributing to corrosion problems and motor starting difficulties.
Although, it has been recognized that some water in the gasoline is desirable since the presence of water will reduce the Octane Requirement Increase (ORI) and will increase the Octane Rating (OR), a hazy blend will result when a commercial alcohol-gasoline blend, e.g., Oxinol 30* gasoline, is contaminated with water, i.e., saturated with water. FNT *Combination alcohol product mfgd. by Arco Chemical Co.
An alcohol-gasoline blend may become hazy when any moisture comes in contact with it when the alcohol-gasoline is in storage tanks or is being transported, in any system, e.g., trucking, etc., or when it comes in contact with other gasoline blends, e.g., unleaded gasolines, other grades of gasolines, etc., or when the ambient temperature suddenly drops below about 35.degree. F.
Thus, an object of the present invention is to provide a process for converting a hazy water-saturated alcohol-gasoline into a clear stable gasoline blend down to sub-zero temperatures, i.e., less than 0.degree. F., and improve the Octane Rating (OR) of the gasoline.
2. Disclosure Statement
U.S. Pat. No. 3,876,391 discloses clear motor fuel microemulsions comprising gasoline, water, two different surfactants and a water soluble and insufficiently gasoline soluble additive. The gasoline does not contain any alcohol.
U.S. Pat. No. 4,384,872 discloses a motor fuel composition comprising gasoline, alcohol, and an interfacial modifying agent. The gasoline does not contain any water.
U.S. Pat. Nos. 3,822,119, 3,876,391, 4,002,435, and 4,445,908 disclose the addition of an excessive amount of surfactants and alcohol to manufacture a clear emulsion of methanol-water-gasoline, or an excessive amount of alcohol to solubilize water into gasoline whereby a lean fuel/air ratio is obtained resulting in an engine's difficult cold start and poor drivability.
U.S. Pat. No. 4,398,920 discloses the addition of an excessive amount of butanol-acetone as a cosolvent for methanol, acetone, and isopropanol and gasoline where severe corrosion and wear will occur in the internal combustion engine besides having a difficult cold start and lack of drivability.